The purpose of the proposed research is to examine the role of parent-child relationships and interaction patterns on the development of very young children's competence in peer interaction. In accordance with attachment theory, it is hypothesized that children develop patterns of relating to their peers based on expectation derived from interactions with their parents. Also, following Vygotsky's cognitive-developmental theory, it is predicted that the early development of communication skills used in peer interactions, such as those involved in resolving conflicts or coordinating play, are guided by parents in early development. The influence of children on family interaction patterns is expected to increase as children gain experience in interactions outside the family. To investigate the proposed links between family and peer interaction a longitudinal study which follows 60 children for three years (from 18 to 54 months) is proposed. The children, who will be in full time day care, will be observed in interactions with both of their parents and with their parents and with their familiar peers in their day care centers five times during this period. Measures of parent's and children's discourse and communication patterns, including responsiveness to others, attention-getting skills, turn-taking patterns, and maintenance of cohesive discourse, will be obtained from videotapes. In addition, parent's and children's styles and skills in resolving conflicts and in coordinating play will be examined. Measures of the quality of the children's family relationships (security of attachment to mother and father, parent ratings of their relationships with the child, and parent's childrearing attitudes) and their peer competence (teacher and peer sociometric ratings) will also be obtained over the course of the study. Four studies aimed at key questions concerning links between parent-child and peer relations are proposed. This research will clarify the interpersonal processes in the family that lead to competence adaptation with peers.